| Flash-Pac Limited. | | 1982 |
| Flashbuy Ltd | Wholesale & retail | 2024 |
| Flashflyers Ltd | Other services | 2026 |
| Flashfresh Ltd | Wholesale & retail | 2025 |
| Flashgroup Inc Ltd | Information & communication | 2017 |
| Flashhaute Ltd | Wholesale & retail | 2020 |
| Flashrabbit Ltd | Manufacturing | 2021 |
| Flashteam Limited | Professional & scientific | 2025 |
| Flashy Finish Ltd | Wholesale & retail | 2025 |
| Flat Homes Property Services Limited | Real estate | 2013 |
| Flat Roof Care Ltd | Construction | 2009 |
| FLAT2SHARE Ltd | Real estate | 2015 |
| Flatbed Services Limited | Real estate | 2024 |
| Flatholm Ltd | Real estate | 2016 |
| Flatout Service Ltd | Manufacturing | 2023 |
| Flats 1-4 Dorchester Court Management Limited | Real estate | 2003 |
| Flats 1-6 Llandough House Freehold Ltd | Households | 2012 |
| Flava Mobile Kitchen Ltd | Hospitality | 2026 |
| Flavio Food and Drinks Limited | Hospitality | 2019 |
| Flavor Tasty Food Ltd | Manufacturing | 2024 |
| Flavour of the Month Limited | Construction | 2010 |
| Flavoureak UK Ltd | Wholesale & retail | 2025 |
| Flawless Acquisitions Ltd | Professional & scientific | 2024 |
| Flawless Design & Build Limited | Construction | 2019 |
| Flawless Finish Installations Ltd | Construction | 2024 |
| Flawless Nails & Beauty Salon Limited | Wholesale & retail | 2019 |
| Flawless Plumbing Services Ltd | Construction | 2024 |
| FLD Construction Ltd | Construction | 2018 |
| FLD Investments Limited | Administrative & support | 2017 |
| Fleabag & Furball Ltd | Wholesale & retail | 2020 |
| Fleek Ltd | Transport & logistics | 2012 |
| Fleek Soft Ltd | Wholesale & retail | 2020 |
| Fleet Edge Ltd | Wholesale & retail | 2025 |
| Fleet Trading Limited | Wholesale & retail | 2002 |
| Fleetev Limited | Wholesale & retail | 2021 |
| Fleeting Ltd | Information & communication | 2019 |
| Fleming Gold U.K Ltd | Wholesale & retail | 2020 |
| Flentex Limited | Information & communication | 2020 |
| Fleom Limited | Wholesale & retail | 2021 |
| Flesher Jenkins Ltd | Real estate | 2025 |
| Fletcher Hunt (Bristol) Limited | | 1986 |
| Fletcher Law Ltd | Professional & scientific | 2016 |
| Fletcher Morgan Consultants Limited | Other services | 2020 |
| Fletchers Bakeries Investments Limited | Financial services | 2006 |
| Fletchers Bakeries Limited | Manufacturing | 1930 |
| Fleur DE LYS Bridal Limited | Wholesale & retail | 2008 |
| Fleur Pro Marketing Ltd | Wholesale & retail | 2025 |
| Fleur Rouge Events Ltd | Hospitality | 2025 |
| Flex Aura Ltd | Wholesale & retail | 2025 |
| Flex Drivers Limited | Professional & scientific | 2014 |
| Flex Ecom Ltd | Wholesale & retail | 2022 |
| Flex People Ltd | Administrative & support | 2020 |
| Flexfi Financial Ltd | Financial services | 2025 |
| Flexi Muscles Ltd | Wholesale & retail | 2025 |
| Flexia Solutions Ltd | Information & communication | 2012 |
| Flexibility HR Services Ltd | Administrative & support | 2021 |
| Flexibility Services Ltd | Wholesale & retail | 2021 |
| Flexible Engineering Limited | | 1977 |
| Flexible Finance (Holdings) Ltd | Financial services | 2024 |
| Flexible Finance (UK) Limited | Financial services | 2009 |
| Flexistore (Cardiff) Ltd | Administrative & support | 2010 |
| Flexit Removals Ltd | Transport & logistics | 2024 |
| Flexnmove Limited | Health & social care | 2025 |
| Flexshipr Ltd | Transport & logistics | 2021 |
| Flexstream Limited | Other services | 2025 |
| Flexwear Scrubs Ltd | Wholesale & retail | 2025 |
| Flexy Franchises Limited | Wholesale & retail | 2020 |
| Flexy Healthcare Staffing Ltd | Administrative & support | 2017 |
| Flick the Switch Limited | Information & communication | 2004 |
| Flickra Ltd | Wholesale & retail | 2025 |
| Flickstar Holding Ltd | Financial services | 2025 |
| Flight (FPC3) Ltd | Information & communication | 2024 |
| Flight Fourtify Ltd | Other services | 2025 |
| Flight Gateway Hub Limited | Administrative & support | 2025 |
| Flight House Centre Limited | Administrative & support | 2025 |
| Flight Saver Centre Limited | Administrative & support | 2026 |
| Flightcentral Ltd | Information & communication | 2025 |
| Flightlink Travel Ltd | Transport & logistics | 2011 |
| Flik Design Ltd | Professional & scientific | 2014 |
| Flinch Ltd | Information & communication | 2013 |
| Flint Dental Surgery Limited | Health & social care | 2010 |
| Flint Hospitality Limited | Hospitality | 2016 |
| Flint Motor Services Limited | Wholesale & retail | 2014 |
| Flint Motorcycles Limited | Wholesale & retail | 2015 |
| Flintec UK Limited | Wholesale & retail | 1990 |
| Flinton Road Solar Limited | Energy | 2024 |
| Flintshire MOT Centre Ltd | Wholesale & retail | 2020 |
| Flintshire Schools Holdings Limited | Financial services | 2022 |
| Flintshire Schools Limited | Construction | 2022 |
| Flipper.Cp Ltd | Wholesale & retail | 2025 |
| Flipsale Trading Ltd | Wholesale & retail | 2025 |
| Flitime International Technology and Trade Group Co. Ltd | Wholesale & retail | 2022 |
| FLO & Comp Ltd | Transport & logistics | 2017 |
| Floating Sound Bath UK Ltd | Education | 2024 |
| Floating Staircases Ltd | Manufacturing | 2021 |
| Floc Games Limited | Wholesale & retail | 2026 |
| Flock Film Ltd | Information & communication | 2023 |
| Flock Media Ltd | Information & communication | 2024 |
| Flocosu Couriers Ltd | Transport & logistics | 2018 |
| Floderma Limited | Wholesale & retail | 2025 |